meat/tests/actors.test.ts

import { expect, test } from "bun:test"
import { Actor, type Actor as RuntimeActor, type ActorDefinition } from "engine/scene/Actor"

type World = { updates: string[] }

const numberDefinition: ActorDefinition<{ value: number }, World> = {
  prototype: { groups: [], radius: 1, minY: 0, maxY: 1 },
  update: (state, _dt, world) => {
    state.value++
    world.updates.push(String(state.value))
  },
  transform: (state) => ({ x: state.value, y: 0, z: 0, heading: 0, scale: 1 }),
}

const textDefinition: ActorDefinition<{ value: string }, World> = {
  prototype: { groups: [], radius: 1, minY: 0, maxY: 1 },
  update: (state, _dt, world) => {
    state.value += "!"
    world.updates.push(state.value)
  },
  transform: (state) => ({ x: state.value.length, y: 0, z: 0, heading: 0, scale: 1 }),
}

test("one actor collection safely erases unrelated state types", () => {
  const actors: RuntimeActor<World>[] = [
    Actor.create(numberDefinition, { value: 1 }),
    Actor.create(textDefinition, { value: "a" }),
  ]
  const world: World = { updates: [] }

  for (const actor of actors) {
    Actor.update(actor, 1, world)
  }

  expect(world.updates).toEqual(["2", "a!"])
  expect(Actor.transform(actors[0]).x).toBe(2)
  expect(Actor.transform(actors[1]).x).toBe(2)
})